You can select any portion of a document.
To select a portion of a document in the Editing Window, do the following:
Click the beginning of the portion in the Editing Window.
Indicate the end of the portion in the Editing Window one of these ways:
Holding down the Shift key, click the end of the portion.
Holding down the left mouse button, drag the mouse till the end of the portion.
When the end or the beginning of a portion crosses an element's border, selection will depend on the Balance Selection mode.